In a liquid crystal display device, when light from a backlight, light from an outside (natural light), or light in which the light from the backlight and the natural light is scattered by a liquid crystal layer (scattered light) is incident on a channel region of a thin film transistor, a characteristic of the thin film transistor generally changes, which results in degradation of display quality. For example, a method for enlarging a region of a black matrix or a method for providing a light shielding layer on a backlight side of the thin film transistor is conceivable as a method for solving the problem. However, in these methods, an opening ratio of a pixel is degraded, or a configuration becomes complicated.
A technique, in which two display panels overlap each other and an image is displayed on each display panel based on an input video signal, is conventionally proposed to improve contrast of a liquid crystal display device (for example, see International Publication WO2007/040127). Specifically, for example, a color image is displayed on a front-side (observer-side) display panel in two display panels disposed back and forth, and a black-and-white image is displayed on a rear-side (backlight-side) display panel, thereby improving contrast. In a liquid crystal display device including two display panels, the display panel disposed on the backlight side is easily influenced by the back light or the scattered light, and the characteristic of the thin film transistor is easy to change.
Thus, in the conventional liquid crystal display device, the display quality is degraded due to the light incident on the channel region of the thin film transistor.
The present disclosure is made in view of the above situation, and an object of the present disclosure is to provide a liquid crystal display device that can prevent the degradation of the display quality due to the light incident on the channel region of the thin film transistor.